This will most likely be of interest to members of the V8 lumper crowd who have a trip computer that does not work properly anymore. Actually the TC is a great little gadget once you understand how to use it. But when you install a v8 in the car there are a few things to do to make it functional again. Changing a capacitor inside the interface for the correct one and everything works again. The interface is connected to the Jaguar ECU where it gets a copy of the pulse/ interval injector signal, disconnect from Jag ecu and connect to GM ECM (PCM) to get a copy of the GM injector pulse/frequency signal.
I have more info that I have gleaned from the internet over the years should anyone want more in depth knowledge.

 

the following study has been floating since the early 1990's on paper, and then online:

Jaguar XJ6 SIII trip computer details

 

Thanks Jose I already have that one in my Jaguar folder on my PC. Great info..The big question is,... which capacitor value fits my fuel injection (TBI, TPI, LT1 or other...) characteristics ?

 

only one person I know who could solve that: Mike at jaguarclock.com

 

Jose
Fiddling with the clock has nothing to do with making the TC read correctly when the car has been converted to a GM V8.
The issue is, what value of capacitor inside the interface, is to be used with what engine / EFI combination ?
Fine tuning this capacitor value is a trial / error exercise over several fuel fill ups ..eventually the right combination will enable the TC to work / read correctly. Capturing a new pulse /frequency signal from the V8 efi system and feeding it to the interface unit is an issue as well, though a minor one.
I visited your website and if you are not aware, some of the hyper links do not work.

 

Hi,

I came across this older thread. Which capacitator ecactly is to be changed to adjust the interface? My problem is that my trip computer (more likely my interface) in my 1992 XJ12 Series 3 is producing wrong consumption values. It depends a bit on running condition but the fuel consumed according to the trip computer is about 15-20% less that the actual consumption at the pump

Thankyou for any advice

Best
Peter

 

Alyn, I will check the links to see what the issue is.
Thanks.
What I meant is that Mike is an electronic wizard and he can figure it out. His business is repairing classic Jaguar clocks but this has nothing to do with the trip computer clock.

 

I enclose a picute of the interface - which are the capacitors to be changed? the blue one?